JP6662133B2 - Mechanical smoke exhaust system and fire prevention structure - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical smoke exhaust system applied to a building having a stairwell that penetrates a plurality of floors, and a fire suppression structure including the mechanical smoke exhaust system.

  2. Description of the Related Art In recent years, in the field of architecture, an architectural structure that creates an open and comfortable space by providing a vent space (atrium as a specific example) that penetrates a plurality of floors has attracted attention. Regarding this type of building, various fire countermeasure structures have been proposed for preventing the spread of fire and the spread of smoke.

  For example, Patent Literature 1 discloses a smoke exhaust system in which a partition is provided on a floor facing the upper side of a blow-out space to provide smoke and that smoke is discharged from a smoke outlet near an upper end of the blow-up space. Has been proposed. Further, there is a description that a mechanical smoke exhaust device including a smoke exhaust duct and a smoke exhaust fan may be provided in a room for each floor.

JP 2001-104499 A (FIG. 1, [0018], [0022], etc.)

  However, this type of mechanical smoke exhaust device is provided with a self-closing fire prevention damper having a temperature fuse in order to prevent the surroundings from overheating or spreading due to high-temperature smoke. When this fire prevention damper is in the “closed” state, the inhalation of smoke from the smoke outlet stops, and the smoke stays in the fire room. After that, the retained smoke flows out toward the blow-by space communicating with the fire room.

  In this case, it is necessary to take a thorough fire countermeasure at a location adjacent to the blow-by space, assuming that a large amount of high-temperature smoke may flow into the blow-by space. Specifically, it is necessary to provide a fire prevention section (including an area section and a pit section) specified by law and to adopt a section method according to the type of the section.

  For example, by providing a partition with a fireproof material or providing a fireproof shutter or a fireproof door, sufficient fire prevention measures can be taken, but there is a problem that construction costs rise or design flexibility is reduced.

  The present invention has been made in view of the above-described problems, and relates to a fire prevention measure for a building having a stowage space, and provides a mechanical smoke exhaust system and a fire prevention structure capable of simultaneously suppressing an increase in construction cost and a decrease in design flexibility. The purpose is to provide.

  The “mechanical smoke exhaust system” according to the present invention is a system applied to a building having a stairwell that penetrates a plurality of floors, and is configured to reduce smoke remaining in a room adjacent to the stairwell on at least one floor. A first smoke guiding means for guiding, a second smoke guiding means for guiding smoke staying in the blowing space, and a smoke collected and discharged by the first smoke guiding means and the second smoke guiding means. A smoke exhauster is provided, and the first smoke guiding means includes a fireproof duct.

  As described above, since the first smoke guiding means is configured to include the fireproof duct, the fireproof duct is less likely to be damaged or burnt out, and further overheat or spread around the fireproof duct is less likely to occur. There is no need to stop the smoke operation. In this case, the smoke generated from the room is discharged not only from the flow path through the blow-by space but also from the room through the flow path toward the first smoke guiding means.

  That is, since the smoke generated in the room is dispersed into the two flows, the amount of smoke passing through the blow-out space is reduced by that much, and the heat load on the adjacent portion of the blow-out space is reduced. As a result, it is possible to take measures such as reducing the number of fire prevention sections in a building and exempting fire prevention sections. As a result, it is possible to simultaneously suppress a rise in construction costs and a decrease in the degree of freedom in designing with respect to a fire countermeasure in a building having a stairwell.

  Further, the smoke exhauster is disposed above the building, and the first smoke guiding means includes a plurality of smoke outlets provided for each floor, each of the smoke outlets and the smoke exhauster. May be provided with a vertical duct that forms an airway between them.

  The apparatus further comprises smoke control means for performing opening / closing control on each of the smoke outlets, wherein the smoke control means performs opening control on the smoke outlet corresponding to the floor where the source of smoke is located. At the same time, the closing control may be performed on the remaining smoke exhaust ports. By extracting smoke from a position close to the generation source, that is, a position where the concentration is relatively high, a highly efficient smoke discharge operation can be performed.

  An outside air guide having an outside air intake provided outside the building, an outside air duct forming an air passage between the outside air intake and the smoke exhauster, and an outside air damper provided in the middle of the outside air duct. Means may further be provided, and the smoke evacuator may discharge smoke diluted by outside air from the outside air guiding means. By diluting the high temperature smoke with the outside air, the temperature of the gas reaching the smoke evacuator is significantly reduced, and the heat load on the smoke evacuator can be reduced.

  Further, a thermometer that measures the temperature of the smoke exhauster or its surroundings, and when the temperature measured by the thermometer exceeds a threshold, performs opening control on the outside air damper, and when the temperature does not exceed the threshold. The apparatus may further include outside air intake control means for performing closing control on the outside air damper. By controlling the opening and closing of the outside air damper using the temperature measurement result by the thermometer, it is possible to achieve both the efficiency of the smoke exhaust operation and the reduction of the heat load.

  The “fire prevention structure” according to the present invention includes any one of the above-described mechanical smoke exhaust systems and one or more partitions disposed on the front end side of the floor for each floor and separating the blow-off space and the room. Prepare.

  In addition, one or more overhangs provided at a position close to the partition and configured to extend a surface of the floor toward the blow-out space may be further provided. Smoke in the room flows out toward the blow-off space along the floor and the surface of the overhang. Here, the smoke is deprived of heat by the overhanging portion by contacting the lower surface of the overhanging portion, so that when reaching the partition, the temperature of the smoke is sufficiently reduced. Further, since the overhanging portion is provided at a position close to the partition, it is possible to prevent the rising smoke from directly contacting the partition, and reduce the heat load applied to the partition.

  ADVANTAGE OF THE INVENTION According to the mechanical smoke exhaust system and the fire countermeasure structure which concern on this invention, about the fire countermeasure of the building which has a stairwell, it can suppress simultaneously the rise of construction cost and the fall of design freedom.

1 is an overall configuration diagram of a building in which a fire prevention structure according to a first embodiment is incorporated. It is explanatory drawing regarding the behavior of the smoke accompanying the operation | movement of the mechanical smoke exhaust system shown in FIG. It is the whole block diagram of the building in which the fire prevention structure concerning a 2nd embodiment was incorporated. FIG. 4 is an explanatory diagram regarding an operation state of the mechanical smoke exhaust system illustrated in FIG. 3. It is the whole block diagram of the building in which the fire prevention structure concerning a 3rd embodiment was incorporated. It is explanatory drawing regarding the behavior of the smoke in the periphery of the overhang part shown in FIG. It is a sketch of the experimental model used for the effect confirmation. It is a figure which shows the height distribution of the temperature rise amount in a blowing space.

  Hereinafter, a mechanical smoke exhaust system according to the present invention will be described with reference to the accompanying drawings, taking a preferred embodiment in relation to a fire prevention structure.

[First Embodiment]
First, a fire prevention structure 10 according to a first embodiment will be described in detail with reference to FIGS.

<Configuration of fire prevention structure 10>
FIG. 1 is an overall configuration diagram of a building 12 in which a fire protection structure 10 according to the first embodiment is incorporated. In this drawing, a floor 14, a wall 16, a ceiling 18, and floors 20, 22 are schematically shown as main structural parts of the building 12. Inside the building 12, there is formed a blow-out space 26 penetrating each of the plurality of floors 24a, 24b, 24c.

  The lower floor 24a is provided with a chamber 28a adjacent to the blow-out space 26. On the middle floor 24b, a room 28b adjacent to the blow-out space 26 is provided. On the upper floor 24c, a room 28c adjacent to the blow-out space 26 is provided. Note that an evacuation door 30 for evacuation outside the building 12 is disposed in the room 28c.

  A partition 32 made of glass is provided at a position on the front end side of the floor 20 facing the blow-off space 26. A partition 34 made of glass is provided at a position facing the blow-off space 26 on the tip side of the floor 22. Thus, the chambers 28 b and 28 c are physically separated from the blow-out space 26.

  The fire prevention structure 10 constructed in the building 12 includes a mechanical smoke exhaust system 40 using a mechanical smoke exhaust system in addition to the partitions 32 and 34 described above. Here, the “mechanical smoke exhaust method” means a method in which the smoke exhaust device 46 is operated to extract smoke S in a portion to be exhausted, thereby exhausting smoke outside the building 12.

  The mechanical smoke exhaust system 40 is guided by first smoke guiding means 42 for guiding the smoke S staying in the chambers 28a to 28c, and second smoke guiding means 44 for guiding the smoke S staying in the blow-out space 26. It includes a smoke exhauster 46 that collects the smoke S and discharges it to the outside.

  The first smoke guiding means 42 includes a smoke outlet 48a provided near the wall 16 contacting the room 28a, a smoke outlet 48b provided near the wall 16 contacting the room 28b, and a wall 16 contacting the room 28c. And a vertical duct 50 which forms an air path between each of the smoke outlets 48a to 48c and the smoke exhauster 46 and is disposed outside the wall 16. You.

  The vertical duct 50 is a fire-resistant duct (hereinafter, fire-resistant duct) whose main pipe extends in the height direction toward the roof of the building 12 and branches at a plurality of height positions. The heat-resistant temperature of the vertical duct 50 is preferably higher from the viewpoint of fire prevention, and is generally 800 to 1200 ° C. As a specific example, the vertical duct 50 is configured by winding a refractory coating material (rock wool of 25 mm or more) around a steel plate duct of 1.5 mm or more.

  The second smoke guiding means 44 forms a smoke outlet 52 provided in the vicinity of the ceiling 18 in contact with the blow-off space 26, an air passage between the smoke outlet 52 and the smoke exhauster 46, and the outside of the ceiling 18. And a smoke exhaust damper 56 provided in the middle of the horizontal pulling duct 54.

  The smoke exhauster 46 is connected to the vertical duct 50 and the horizontal duct 54, respectively, and sucks the smoke S in the vertical duct 50 and the horizontal duct 54, and discharges the smoke S from a smoke exhaust outlet (not shown). It should be noted that the heat-resistant temperature of the smoke exhauster 46 differs depending on the model (centrifugal type or axial flow type), but is generally 600 to 800 ° C. or lower.

  The mechanical smoke emission system 40 further includes a PLC (Programmable Logic Controller) control panel 58 (smoke emission control means) capable of controlling each component device, and an emergency power supply 60 separate from a commercial power supply. Specifically, the PLC control panel 58 performs drive control of the smoke exhaust device 46, open / close control of the smoke outlets 48a to 48c, 52, and open / close control of the smoke exhaust damper 56.

<Operation of the mechanical smoke exhaust system 40>
Next, the operation of the mechanical smoke exhaust system 40 in the event of a fire will be described with reference to FIG. For example, when a fire F is generated from the inside of the room 28a, the mechanical smoke exhaust system 40 is operated to ensure the safety of the occupants M in evacuation.

  Generally speaking, in order to prevent the surroundings from being overheated or spread due to the high temperature smoke S, the smoke exhaust vertical duct may be provided with a self-closing fire damper having a temperature fuse. . However, it should be noted that in each of the embodiments including the first embodiment, the fire prevention damper is not provided, and the mechanical smoke exhaust via the first smoke guiding means 42 is not stopped.

  As shown in FIG. 2, the PLC control panel 58 performs “open” control on the smoke exhaust damper 56 and operates the smoke exhaust device 46. The PLC control panel 58 further performs "open" control on the smoke outlet 48a corresponding to the floor 24a where the generation source (fire F) of the smoke S is located, and smoke exhaust corresponding to the remaining floors 24b and 24c. "Close" control of the ports 48b and 48c is performed.

  A part of the generated smoke S stays in the chamber 28 a and flows out along the surface of the floor 20 toward the blow-out space 26. Thereafter, the smoke S flowing out of the chamber 28a rises while causing convection, and stays above the blow-by space 26 (near the ceiling 18).

  Since the vertical duct 50 is a refractory duct, the refractory duct is less likely to be damaged or burnt out, and furthermore is less likely to overheat or spread around the refractory duct, and it is not necessary to stop the smoke guiding operation by the first smoke guiding means 42. In this case, the smoke S generated from the interior of the chamber 28a is discharged not only through the flow path passing through the blow-out space 26 but also through the flow path from the interior of the chamber 28a toward the first smoke guiding means 42.

  That is, since the smoke S generated in the chamber 28a is dispersed into the two flows, the amount of the smoke S passing through the blow-off space 26 is reduced by that amount, and the adjacent portion of the blow-off space 26 (for example, the partition 32, 34) The heat load applied to 34) is reduced. As a result, it is possible to take measures such as reducing the number of fire prevention sections in the building 12 and exempting the fire prevention sections.

  Specifically, as the fire protection structure 10, the partitions 32 and 34 do not need to be made of a refractory material, and for example, glass can be used. In addition, depending on the smoke emission capacity of the mechanical smoke emission system 40 or the structure of the building 12, it is not necessary to provide a fire shutter or a fire door separately from the partitions 32,.

  Note that the smoke exhauster 46 is configured to be operable by the emergency power supply 60 when the supply of power from the commercial power supply (main power supply) is stopped. This realizes “unstoppable mechanical smoke exhaust” via the first smoke guide 42 and / or the second smoke guide 44.

<Effects of First Embodiment>
As described above, the mechanical smoke exhaust system 40 is applied to [1] the building 12 having the blow-off space 26 penetrating over a plurality of floors 24a to 24c, and [2] the blow-off space at at least one floor 24a to 24c. First smoke guiding means 42 for guiding the smoke S staying in the chambers 28a to 28c adjacent to 26, [3] second smoke guiding means 44 for guiding the smoke S staying in the blow-off space 26, [4] ] A smoke exhauster 46 is provided for collecting and discharging the smoke S guided by the first smoke guiding means 42 and the second smoke guiding means 44. [5] The first smoke guiding means 42 includes a vertical duct 50 (fireproof duct). It is comprised including. Thereby, regarding the fire countermeasures of the building 12 having the blow-out space 26, it is possible to simultaneously suppress a rise in construction cost and a decrease in the degree of freedom in design.

  Further, the smoke exhauster 46 is disposed above the building 12, and the first smoke guiding means 42 includes a plurality of smoke outlets 48a to 48c provided for each floor 24a to 24c, and each smoke exhaust outlet. A vertical duct 50 may be provided to form an air passage between the smoke exhausters 46 and 48 a to 48 c.

  The mechanical smoke exhaust system 40 further includes a PLC control panel 58 (smoke exhaust control means) for performing opening / closing control on each of the smoke exhaust ports 48a to 48c. The opening control may be performed on the smoke outlet 48a corresponding to the floor 24a where the fire F) is located, and the closing control may be performed on the remaining smoke outlets 48b and 48c. By extracting the smoke S from a position close to the fire F, that is, a position having a relatively high concentration, a highly efficient smoke discharging operation can be performed.

[Second embodiment]
Next, a fire prevention structure 70 according to a second embodiment will be described with reference to FIGS. This fire protection structure 70 corresponds to an improved example of the first embodiment (fire protection structure 10). In addition, about the structure equivalent to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

<Configuration of fire prevention structure 70>
FIG. 3 is an overall configuration diagram of the building 12 in which the fire protection structure 70 according to the second embodiment is incorporated. In the second embodiment, the structure of the building 12 is the same as that of the first embodiment (the building 12), but the configuration of the mechanical smoke exhaust system 72 is different from that of the first embodiment (the mechanical smoke exhaust system 40).

  The mechanical smoke exhaust system 72 includes an outside air guide 74 that guides outside air, in addition to the first smoke guide 42, the second smoke guide 44, and the smoke exhaust 46. The outside air guide 74 is provided outside the building 12, an outside air duct 78 forming an air passage between the outside air intake 76 and the smoke exhauster 46, and provided in the middle of the outside air duct 78. And an outside air damper 80.

  The smoke exhauster 46 is connected to a junction 82 where the vertical duct 50, the horizontal duct 54, and the outside air duct 78 join together, sucks the smoke S diluted by the outside air from the outside air duct 78, and also has a smoke exhaust outlet (not shown). Discharged from

  The mechanical smoke exhaust system 70 includes, in addition to the emergency power supply 60, a thermometer 84 that measures the temperature of the smoke exhaust device 46 or its periphery (in this case, the junction 82), and a PLC control panel 86 that can control each component device. (Smoke exhaust control means, outside air intake control means). Specifically, the PLC control panel 86 performs drive control of the smoke exhaust device 46, open / close control of the smoke outlets 48 a to 48 c, 52, open / close control of the smoke exhaust damper 56, and open / close operation of the outside air damper 80.

<Operation of the mechanical smoke exhaust system 72>
Next, the operation of the mechanical smoke exhaust system 72 when a fire occurs will be described with reference to FIG. For example, when fire F is generated from the inside of the room 28a, the mechanical smoke exhaust system 72 is operated to ensure the safety of the occupant M in the evacuation.

  As described in the first embodiment, when mechanical smoke exhaustion via the first smoke guiding means 42 is continued, there is a concern about a heat load applied to the smoke exhauster 46. That is, when the heat-resistant temperature of the vertical duct 50 is higher than the heat-resistant temperature of the smoke exhaust device 46, it is noted that the high-temperature smoke S may cause the smoke exhaust device 46 to malfunction or break.

  As shown in FIG. 4, the PLC control panel 86 performs “open” control on the smoke exhaust damper 56 and activates the smoke exhaust device 46. The PLC control panel 86 further performs “open” control on the smoke outlet 48a corresponding to the floor 24a where the generation source (fire F) of the smoke S is located, and smoke exhaust corresponding to the remaining floors 24b and 24c. "Close" control of the ports 48b and 48c is performed.

  The PLC control panel 86 further controls the opening and closing of the outside air damper 80 according to the temperature of the junction 82 that is sequentially measured by the thermometer 84. Specifically, the PLC control panel 86 performs “open” control on the outside air damper 80 when the temperature exceeds the threshold, and performs “close” control on the outside air damper 80 when the temperature does not exceed the threshold. . The threshold is set to an arbitrary value (for example, 500 ° C.) lower than the heat-resistant temperature of the smoke exhaust device 46.

  When the outside air damper 80 is in the “open” state, the smoke S is diluted by the outside air from the outside air guide 74. That is, after the high-temperature smoke S flows in the order of the chamber 28a, the smoke exhaust port 48a, the vertical duct 50, and the junction 82, when the smoke S reaches the smoke exhaust device 46, the temperature of the smoke S is sufficiently reduced. Thereby, the heat load applied to the smoke exhauster 46 can be reduced.

  On the other hand, when the outside air damper 80 is in the “closed” state, the smoke S is not diluted by the outside air from the outside air guiding unit 74. In other words, by extracting smoke S having a high concentration as it is, a highly efficient smoke discharge operation can be performed. In addition, even in this “closed” state, the effect of lowering the temperature of the smoke S is obtained. This is because the smoke S in the blow-off space 26 having a relatively low temperature is mixed at the junction 82.

<Effects of Second Embodiment>
As described above, similarly to the first embodiment (the mechanical smoke exhaust system 40), the mechanical smoke exhaust system 72 is applied to the building 12 having [1] the blow-by space 26 penetrating over a plurality of floors 24a to 24c. , [2] a first smoke guide means 42, [3] a second smoke guide means 44, and [4] a smoke exhauster 46. [5] The first smoke guide means 42 includes a vertical duct 50 (fireproof duct). ). Thereby, regarding the fire countermeasures of the building 12 having the blow-out space 26, it is possible to simultaneously suppress a rise in construction cost and a decrease in the degree of freedom in design.

  The mechanical smoke exhaust system 72 includes [6] an outside air inlet 76 provided outside the building 12, an outside air duct 78 forming an air passage between the outside air inlet 76 and the smoke exhauster 46, and an outside air duct 78. [7] The smoke exhauster 46 may discharge the smoke S diluted by the outside air from the outside air guide 74. By diluting the high-temperature smoke S with the outside air, the temperature of the gas reaching the smoke exhaust device 46 is significantly reduced, and the heat load on the smoke exhaust device 46 can be reduced.

  In addition, the mechanical smoke exhaust system 70 performs the opening control on the thermometer 84 that measures the temperature of the smoke exhaust device 46 or its surroundings, and the outside air damper 80 when the temperature measured by the thermometer 84 exceeds a threshold value. In addition, a PLC control panel 86 (outside air intake control means) for performing closing control on the outside air damper 80 when the threshold value is not exceeded may be further provided. By controlling the opening and closing of the outside air damper 80 using the measurement result of the temperature by the thermometer 84, both efficiency of the smoke exhaust operation and reduction of the heat load can be achieved.

[Third embodiment]
Next, a fire protection structure 100 according to a third embodiment will be described with reference to FIGS. This fire countermeasure structure 100 corresponds to an improved example of the first embodiment (fire countermeasure structure 10). In addition, about the structure equivalent to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

<Configuration of fire prevention structure 100>
FIG. 5 is an overall configuration diagram of a building 102 in which a fire protection structure 100 according to the third embodiment is incorporated. In the third embodiment, the configuration of the mechanical smoke exhaust system 40 is the same as that of the first embodiment (the mechanical smoke exhaust system 40), but the structure of the building 102 is different from that of the first embodiment (the building 12).

  The fire prevention structure 100 constructed in the building 102 is provided by the partitions 32, 34, the mechanical smoke exhaust system 40, the overhang portion 104 provided on the floor 28b, and the overhang portion 108 provided on the floor 28c. Be composed.

  The L-shaped overhang portion 104 is provided near the partition 32 and extends the floor 20 toward the blow-out space 112. More specifically, the overhang portion 104 has an extension portion 105 extending horizontally along the surface of the floor 20 and a fence portion 106 extending upward from the distal end side of the extension portion 105.

  The L-shaped overhang 108 is provided near the partition 34 and extends the floor 22 toward the blow-out space 112. More specifically, the overhang portion 108 has an extension portion 109 extending horizontally along the surface of the floor 22 and a fence portion 110 extending upward from the distal end side of the extension portion 109.

  In this manner, by providing the overhang portions 104 and 108 for each of the floors 24b and 24c, an intermediate region 114 is formed between the blow-out space 112 and the partition 32, and an intermediate region 116 is formed between the blow-out space 112 and the partition 34. Is formed.

  Note that the overhang portions 104 and 108 are not limited to the example in FIG. 5 and may have any shape or size. Regarding the material of the overhang portions 104 and 108, the type of material is not limited as long as it has a certain degree of heat resistance or strength.

<Behavior of smoke S when a fire occurs>
FIG. 6 is an explanatory diagram regarding the behavior of the smoke S around the overhang portion 104 shown in FIG. The smoke S in the chamber 28a flows out toward the blow-out space 112 along the surface of the floor 20 and the overhang portion 104. Here, the smoke S is deprived of heat by the overhanging portion 104 by coming into contact with the lower surface of the extension portion 105 or the side surface of the fence portion 106, and the jetting width of the air current is expanded by entraining the surrounding air.

  That is, after the high-temperature smoke S flows in the order of the chamber 28a, the blow-out space 112, and the intermediate region 114, the temperature of the smoke S is sufficiently lowered when reaching the partition 32. Further, since the overhang portion 104 is provided at a position near the partition 32, it is possible to prevent the rising smoke S from directly contacting the partition 32, and reduce the heat load applied to the partition 32.

<Effect confirmation>
Subsequently, in order to confirm the effect of the overhang portions 104 and 108, a model of the fire prevention structure 100 was manufactured and an experiment was performed.

  FIG. 7 is a sketch of the experimental model used for confirming the effect. Specifically, FIG. 7A is a plan view of the first floor, and FIG. 7B is a cross-sectional view taken along line A-A ′. As can be seen from this figure, the experimental model forms a stairwell that passes through three floors and a building with three rooms per floor.

  This experimental model has a size assuming a reduced scale of about 1/3 of the actual size, specifically, a size of 4.5 m in width, 6.3 m in depth, and 3.0 m in height. The blow-off space has a size of 2.275 m in width, 6.3 m in depth, and 3.0 m in height. Each chamber has a size of 2.275 m wide, 2.1 m deep and 1.0 m high.

  Assuming that a fire occurred in a room at the center of the first floor (hereinafter referred to as a fire room), a smoke source was placed in the center of the floor of the fire room. An overhang having a width of 350 mm or 700 mm was attached near the entrance of the fire room.

  FIG. 8 is a diagram showing a height distribution of a temperature rise value in the blow-off space. Specifically, FIG. 8A is a graph showing a difference in the result by the smoke exhaust method, and FIG. 8B is a graph showing a difference in the result by the presence or absence of the overhang portion. The horizontal axis of the graph indicates the temperature rise (unit: ° C.), and the vertical axis of the graph indicates the height (unit: m) from the first floor.

  As shown in FIG. 8 (A), in any of the graphs of “no smoke emission”, “only smoke emission” and “smoke emission + indoor smoke emission”, the temperature rise value becomes larger as the position is higher in the ventilation space. I have. In the case of “no smoke emission”, the maximum was about 75 ° C, while in the case of “only smoke”, the maximum was about 55 ° C, and in the case of “air blowout + indoor smoke”, about 5 ° C maximum Met. In particular, in the case of "blow-out + indoor smoke exhaustion", the temperature rise was dramatically reduced as compared with "blow-out only smoke exhaustion".

  As shown in FIG. 8B, in any of the graphs “without overhang”, “with overhang (350 mm)”, and “with overhang (700 mm)”, the temperature rise value increases as the blow-up space increases. It is getting bigger. In the case of “without overhang”, the maximum was about 50 ° C., while in the case of “with overhang (350 mm)”, the maximum was about 30 ° C., and in the case of “with overhang (700 mm)”, the maximum. It was about 25 ° C. In particular, in the case of "with an overhang", there was a tendency to suppress the overall height distribution evenly as compared with "without the overhang".

<Effects of Third Embodiment>
As described above, the fire prevention structure 100 is [1] the mechanical smoke exhaust system 40 described above, and [2] is disposed on the tip side of the floors 20 and 22 for each of the floors 24b and 24c, and has a blow-out space 112 and a room. It has one or more partitions 32, 34 separating them between 28b, 28c. Thereby, regarding the fire countermeasures of the building 102 having the blow-out space 112, it is possible to simultaneously suppress a rise in the construction cost and a decrease in the degree of freedom in design.

  In addition, the fire prevention structure 100 is provided with [3] one or more overhang portions 104 that are provided near the partitions 32 and 34 and that extend the surfaces of the floors 20 and 22 toward the blow-out space 112. , 108 may be further provided. The smoke S in the chamber 28a (28b) flows out toward the blow-off space 112 along the surface of the floor 20 (22) and the overhang portion 104 (108). Here, since the smoke S is deprived of heat by the overhanging portions 104 (108) by contacting the lower surface of the overhanging portions 104 (108), the temperature of the smoke S is sufficient when reaching the partitions 32, 34. To decline. Further, since the overhang portions 104 and 108 are provided at positions near the partitions 32 and 34, it is possible to prevent the rising smoke S from directly contacting the partitions 32 and 34, and The applied heat load is reduced.

[Note]
It should be noted that the present invention is not limited to the above-described embodiment, and can be freely modified without departing from the gist of the present invention.

10, 70, 100 {Fire prevention structure 12, 102} Building 14, 20, 22 {Floor 24a, 24b, 24c} Floor 26, 112 {Blow-out space 28a, 28b, 28c} Room 32, 34 {Partition 40, 72} Mechanical smoke exhaust system 42 {first smoke guide means 44} second smoke guide means 46 >> smoke exhaust machines 48a, 48b, 48c, 52 >> smoke exhaust port 50 >> vertical duct (fireproof duct) 54 >> horizontal draw duct 56 >> exhaust Smoke damper 58 ‥ PLC control panel (smoke exhaust control means)
60 Emergency power supply 74 Outside air guide means 82 Confluence section 84 Thermometer 86 PLC control panel (smoke exhaust control means, outside air intake control means)
104, 108 overhang 105, 109 extension 106, 110 fence 114, 116 intermediate area F fire (source of smoke) S smoke

Claims (8)

A mechanical smoke exhaust system applied to a building having a stairwell extending through a plurality of floors,
First smoke guiding means for guiding smoke stagnating in a room adjacent to the blow-out space on at least one floor;
Second smoke guiding means for guiding smoke staying in the blow-off space;
A smoke exhauster that collects and discharges the smoke guided by the first smoke guide and the second smoke guide ;
Smoke exhaust control means for controlling smoke exhaust by the first smoke guide and smoke exhaust by the second smoke guide ,
The first smoke guiding means includes a fireproof duct ,
The mechanical smoke exhaust system , wherein the smoke exhaust control unit performs smoke exhaust by the first smoke guide unit and smoke exhaust by the second smoke guide unit in parallel . The smoke evacuator is located above the building,
The first smoke guiding means includes:
Multiple smoke outlets provided for each floor,
The mechanical smoke exhaust system according to claim 1, further comprising: a vertical duct that forms an air passage between each of the smoke outlets and the smoke exhaust device. The smoke exhaust control means is configured to perform opening / closing control on each of the smoke exhaust ports, and performs opening control on the smoke exhaust ports corresponding to the floor where the smoke generation source is located, and performs the remaining control. The mechanical smoke exhaust system according to claim 2, wherein closing control is performed on the smoke exhaust port. An outside air intake provided outside the building, an outside air duct forming an air passage between the outside air intake and the smoke exhauster, and an outside air guide having an outside air damper provided in the middle of the outside air duct. In addition,
The mechanical smoke exhaust system according to any one of claims 1 to 3, wherein the smoke exhaust device emits smoke diluted by the outside air from the outside air guiding unit.   An outside air intake provided outside the building, an outside air duct forming an air passage between the outside air intake and the smoke exhauster, and an outside air guide having an outside air damper provided in the middle of the outside air duct. In addition,
  The smoke outlet is a first smoke outlet,
  The second smoke guiding means,
  A second smoke outlet provided in an upper part of the blow-off space,
  A horizontal duct that forms an air passage between the second smoke outlet and the smoke exhaust device,
  The smoke exhauster is connected to a junction where the vertical duct, the horizontal pulling duct, and the outside air duct join, and discharges smoke diluted by outside air from the outside air guide unit.
  The mechanical smoke exhaust system according to claim 2 or 3, wherein: A thermometer that measures the temperature of the smoke exhauster or its surroundings,
When the temperature measured by the thermometer exceeds a threshold value, performs open control on the outside air damper, and when the temperature does not exceed the threshold value, performs outside control on the outside air damper. The mechanical smoke exhaust system according to claim 4 or 5 , further comprising: A mechanical smoke exhaust system according to any one of claims 1 to 6 ,
A fire prevention structure, comprising: at least one partition disposed on a front end side of a floor for each floor and separating between the blow-out space and the room. 8. The fire countermeasure according to claim 7 , further comprising one or more overhangs provided at a position close to the partition and configured to extend a surface of the floor toward the blow-out space. Construction.

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